how much power can a richmond/doug nash 4+1 take? [Archive] - Chevelle Tech

: how much power can a richmond/doug nash 4+1 take?

Pro Charged Chevelle
Dec 20th, 04, 7:16 PM
hi everyone, im looking at buying a 2002 model richmond 4+1 5 speed and i was wondering if anyone on had any real world experience on how much power they can take. I know they are rated at 450 ft/lbs from richmond, but an older version of hot rod has an ad where the published numbers are 650 ft/lbs.

Pro Charged Chevelle
Dec 22nd, 04, 12:16 AM
nobody is running a 4+1 5 speed?

Dec 22nd, 04, 5:42 PM
I have one in my 76 Cutlass that I bought new. Its behind a well built .030 over 455, and been there since about 1988. Never a problem. I don't abuse it on a regular basis, but I don't baby it either. I use the Cutlass to sometimes tow my 70 Conv on a 16ft flat trailer. Since I installed the tranny, the ONLY time it has ever been out was to replace the clutch. So, I'm thinking maybe a blown HEMI might be able to break one.

Pro Charged Chevelle
Dec 22nd, 04, 9:56 PM
ok cool, sounds like they're pretty tough.i might have a deal worked out for a used one, with 500 miles on it, lakewood scattershield, hays steel flywheel, hays clutch, and hurst shifter for 1800 plus shipping? does that sound like a fair price?

Dec 23rd, 04, 1:08 PM
Sounds like a pretty good deal, if it really only has about 500 miles...

I paid $1450 for mine, (plus shipping) and got a new Long Shifter. Mine's the Road Race version (I think the only difference is better synchros)...

Dec 23rd, 04, 9:49 PM
How much power will they handle? All you throw at it! These are wonderful transmissions with a wide variation of gears to install to change the performance. I have used these transmission for years.

Doug Nash made 2 versions. A street and a strip. The strip was a crash box with no synchros. I have several street versions. I run them with a 2.56 rear gear in the 12 bolt. Since 5th is 1 to 1 in ratio, it's like overdrive cruising down the road at 70 MPH at 1800 RPM. With a 3.27 first gear in the transmission it's like driving with a 3.73 rear gear when pulling from a stop! Truly the best of both worlds for a driver!

There are 2 shifter's offered. The "Long" brand and a Hurst. The Long is the better shifter. The Hurst is still very good.

Doug Nash 5 speeds are easy to identify if they have synchros (street) or do not have synchros (crash box). Look for a big knot/zit on the right side of the box about 2 inches in diamter. If it has the zit, it's a crash box.

Richmond bought the Doug Nash design and inventory. Now sold as Richmond's. Still available new for about $1800 for the transmission only. Shifters are extra. The Richmond 6 speed looks like a 5 speed but is larger and has a true overdrive.

A fine choice for a transmission. Just a little "old school" in trying to accomplish overdrive. I find these used occasionally for less than $1000 with a shifter for a good box. Recently bought one for $500. That's a STEAL!

Dec 23rd, 04, 10:37 PM
Originally posted by mjs13:
Since 5th is 1 to 1 in ratio, it's like overdrive cruising down the road at 70 MPH at 1800 RPM. Wow, that is low rpms for that speed... what size tires do you run? They must be close to 33"

Dec 24th, 04, 1:33 AM
We used to run a Nash strip tranny (crash box) back in my drag racing days 15 - 20 years ago. Had it behind a built to the hilt 302, 13:1 w/ roller, titanium valves/brodix heads, and 5.13's out back in a Vega. We won top honors for our class for 5 straight years. However, we replaced quite a few gears in that tranny but it took a HELL of a lot of punishment!

Pro Charged Chevelle
Dec 24th, 04, 11:21 AM
cool, i think im gonna go for it. it sounds like it will work really well with my stock 2.56s until i put a 12 bolt with new gears into my car..

Dec 26th, 04, 6:02 PM
Running a Doug Nash 5 speed in 5th gear with a 2.56 rear gear is almost EXACTLY the same as running Keisler Tremec HP 5 speed with the 0.70 to 1 overdrive fifth gear and a 3.73 rearend gear or a regular Tremec TKO transmission with the .68 to 1 overdrive fifth gear and 3.70 rear gear.

Same result, just a different way of getting there. Both depending on tire size will run 1800 RPM in 5th at 70 MPH with tires MUCH shorter than 33 inches. 28 inches if memory serves me correct???

Dec 26th, 04, 6:18 PM
Originally posted by Pro Charged Chevelle:
cool, i think im gonna go for it. it sounds like it will work really well with my stock 2.56s until i put a 12 bolt with new gears into my car.. You don't want to go with a real low rear gear with that transmission, it would be like a truck in low range. Try it out with your 2.56's and see what you think, you will probably be happy with it. A 3.27 or 3.55 would be about as low as anyone should go on the street. Plus the 2.56 is a stronger gear set because of the larger pinion.

Dec 26th, 04, 6:33 PM
With a 2.56 rear gear and Nash 5 speed the car will lauch/feel in first gear like it has a 3.70 gear in the rearend compared to your current Muncie 4 speed equipped car. The lowest gear I would EVER consider running with a Nash 5 speed on the street is a 3.08. With 3.31's or lower, first gear becomes almost useless!

The above assumes you are running a 3.27 first gear in the Nash 5 speed which is the factory delivered first gear ratio. It further assumes you are "currently" running a "close ratio" Muncie 4 speed with a stock 2.20 first gear and 3.70 rearend gear for equivalent comparisons. The "feel" and results will be the same!

If you are "currently" running a "wide ratio" Muncie 4 speed with a 2.52 first gear and 3.42 rearend gear, the car will launch/feel the same as the Nash 5 speed/2.56 rearend gear combination for a "close" comparison. Again, the performance will be equivlent! This assumes equivalent tire sizes in all comparisons.

Personally, I have never run anything lower than a 2.73 with a Nash 5 speed on the street. Of course I also was not looking for screaming stop light to stop light performance.

"I" think the Nash 5 speed/2.56 combination is just about perfect for the street. The 2.56/2.73 gears make very strong 12 bolts when running this transmission/rearend combination.

In my mind, the whole point of using a Nash 5 speed all these years is/was to accomplish "overdrive" and reduce the engine RPM when cruising in 5th but NOT loose any performance in first through 4th gears to "4" speed equipped car. I also have found Nash 5 speeds to be MUCH more durable than any Muncie!

Dec 26th, 04, 7:20 PM
As another side note on availability of Richmond/Nash 5 speeds. Jasper Engines previously offered this transmission through their dealer network. You may be able to get as good a deal locally. Worth a call if you are looking!

Dec 27th, 04, 12:42 AM
Originally posted by mjs13:
Both depending on tire size will run 1800 RPM in 5th at 70 MPH with tires MUCH shorter than 33 inches. 28 inches if memory serves me correct??? Not trying to be smart or anything smile.gif , but in the interest of correct information, with any transmission with a 1:1 top gear ratio and 2.56:1 rear gears, you would need tires that were approximately 33.5" in diameter to do 70mph @1800RPM.

If you had a .82 overdrive ratio in a transmission with 2.56 rear gears, then you could do 70mph @1800RPM with only 27.5" tires, for comparison.

As to first gear being useless or too low, that can be very true for some people. Others however really like it. I run a M20 wide ratio (2.52:1 first gear) with 4.10:1 rear gears which is the factory set-up for my car. A first gear shift @3100RPM is about 25pmh with 28" tires. That is an overall first gear ratio of 10.3:1, and for me is a lot of fun. I would not recommend going much lower than that personally, but some love it. It is a personal thing, and experiencing it in differnt cars would be the best way to decide.
Hope that helps. smile.gif

Dec 27th, 04, 6:21 PM
You are correct, at 70 MPH with a 2.56 rearend gear in 5th at 1 to 1 ratio you would run 1825 RPM with a 33 inch tall tire according to the calculator on this site. Poor memory on my part.

At 70 MPH you will ONLY run 2150 RPM with a 2.56 rearend gear in 5th at 1 to 1 ratio with a 28 inch tall tire. This is still as good as many overdrive options available out there. None of the "new" overdrive transmission options are as economical as a good used 5 speed Nash install to replace the stock 4 speed.

Most modern overdrive options require a 3.42 or lower rear gear to make them happy in overdrive and not lug the engine. Therefore you may have to change the rear end gear. I have personally seen far more 3.08 or higher rear gears in Chevelles than I have seen 3.42 or lower gears in stock rearends. Either way, a rear gear change may be needed. 2.56 rear gear 10/12 bolts are a whole lot cheaper than 3.73 rear gear 10/12 bolts in you are buying a rearend to swap in your car. Changing just gears in the rearend will cost the same if buying new gears for the swap. I have personally purchased complete rearends with 2.56/2.73 gears because they were cheap as "most" folks have no need for those gears.

Again, just another way to make your Chevelle more drivable for less money in comparison to "Gear Vendor" overdrives and their install problems, Keisler Tremec 5 speed Transmissions and their cost,, T-56 cost and other alternatives. Most of these options require floorboard surgery to make them fit your car.

Is a Nash the best option avaiable? NO! If the end result driveability, less expense and less install hassle are part of the equation, it certainly is something to consider. It's not glamourous and will not make the magazine write-ups, but that's never been important to me. Ride and drive is what's important!

Dec 27th, 04, 6:39 PM
The only problem I see is that 2.56/2.73 gears and "2-series" posi units are NOT avaialbe new. Doesn't seem to be alot of 2-series posi's, but they can be found and they are rebuildable...

The Richmond is a little nicer (IMO) than the Tremec 5-speeds in that the gear spread is much closer... Those other OD trans have about the same first gear ratio (around 3.27) as the Richmond, but have the OD, so the gears are "further" apart... Too much drop in between each gear for MY taste...

BTW Mike, there are 3 versions of the Richmond 4+1. They also have a Road Race version with supposedly has better (?) synchros than the "street" version and a "standard" 3.04 first gear in stead of 3.27:1...

Dec 27th, 04, 7:11 PM
I did not know Richmond offered 3 versions of the 5 speed. That has certainly occured since Richmond acquired Doug Nash. I have only owned older Nash transmissions of which only 2 versions were available when Doug was manufacturing these transmission here in Nashville. All my transmissions were purchased used.

I almost installed a street 5 speed in my 1966 Shelby GT 350 Vintage road race car when it was rebuilt. I went with a race built Ford toploader instead and now will install a Jericho transmission since they have been made legal in HSR (Historic Sportscar Racing) and SVRA (Sportscar Vintage Racing Association) for the Group 6 cars. The Jericho is good for 1/10 of a second time reduction per corner easy. A great way to pickup a second or more a lap on the longer road courses with no reliability problems. Just jam and go!!!!

How about a Jericho for a street car? You could get an overdrive gear for 4th installed????

Pro Charged Chevelle
Jan 1st, 05, 2:43 AM
well, the richmond 5 speed deal may have to wait as i bought myself another project lol. i picked up a lowered '63 Chevy 1/2 ton long bed on the 26th so the funds for my tranny have been somewhat lowered. The truck is awesome though, 350 bored .040 over with a mild cam backed by a rebuilt TH350 with a shift kit and rebuilt 3.73 rear end.

Jan 2nd, 05, 9:25 PM
The other thing that you can do is over-drive the Road race 5-speed in 4th gear, when you use the optional 2.77 first gear, gear ratio's are:

-----------32% drop
-----------28% drop
-----------26% drop
-----------16% drop
The only problem is the shift pattern, 5th and reverse need to be inverted

1 3 R
| | |
| | |
2 5 4

The other benefit of the 2.77 first gear is, it's a stronger input gear set.
2.77 uses a 27 tooth input/ 31 tooth cluster
3.04 uses a 22 tooth input/ 37 tooth cluster.

The nice thing about the short over-drive is you won't drop out of the torque curve of the motor.
I'm building one right now and hopefully try it out this spring if I can get all my customer tranny's done...
Just a little different way of looking at things...Crash